Today's greenhouse tasks were confined to caulking and insulating the greenhouse such that precious heat does not escape - and also to prevent snow from working its way in during the long winter. We will likely be caulking on a regular basis until we leave so as to seal up every possible crack in the structure.

The day started out cold and drizzly. For every nice day we get, we seem to have to suffer through two as penance. This day we did not have to wait - the weather turned wonderful once again after a few hours. Even before it got nice, the greenhouse managed to get up to 23C even with overcast skies. Amazing.

Today also marked the departure of camp carpenter extraordinaire A.C. Hitch and Vicky Glass, paramedic, stand-in camp medical officer, and all around greenhouse assembly helper. While Marc and I had test-assembled the greenhouse in April in California (including a wooden sill) we had not built the underlying support platform, attached all of the Lexan, or finished up the innumerable small details that went into the assembly.

Having assembly instructions that were often confusing didn't help things. Having someone like A.C. who has assembled many things in both the arctic and in Antarctica was a godsend - especially when some of our lumber went missing - or parts simply did not go where thy were supposed to. The successful assembly of this structure in this bizarre environment owes more to her than anyone else.

Later in the afternoon I went over to the "Office Tent" to have a blood sample taken. I'm one of 10 HMP team members who've agreed to be part of a pilot study (the "Haughton Mars Immune Assessment") being done by NASA's Johnson Space Center and Ames Research Center, Wylie Laboratories, and the SETI Institute. We had all given blood samples a month before we left home and would be giving samples again a month or so after we returned home. Our camp doctor, Lt. Col. George Martin, MD, took the blood sample and Brian Crucian, from Wyle Laboratories, processed the samples.

Formally titled "Assessment of Immune System Dysregulation and Viral Reactivation During Simulated Advanced Human Exploration Missions",
this study uses the HMP Base Camp as an analog for extended duration spaceflight to see how our immune systems function when we are isolated in a stressful environment with difficult work schedules. Over the past four decades, space travelers have repeatedly shown alterations in their immune system function during, and after spaceflight. I was more than happy to do my part to help.

On my way to my tent that night, I stopped to drink in the surroundings. Being as busy as I have been here, I have neglected the task of simply stopping to truly experiencing this wondrous place. Earlier in the day I recalled something that former Astronaut Jim Bagain had said in an article "Everest on Orbit" I wrote which was published in 1993 in Climbing Magazine:

"To be honest, I remember more about my time on Mt. McKinley than I do about either of my missions."

After remembering this, I was determined not to let the detail of this trip (i.e. my 'mission') pass unnoticed - especially since I may never get to see this place again. In addition to snapping innumerable photos (more than 2,500 by the time I got home) I did my best to capture things in writing - or stop and drink things in such that they'd remain etched in my memory. I now sought to redouble my efforts. Half of my stay here still lay before me.

One of the things about this place is the ever-changing vistas one sees. This is a place of rock, soil, snow, sun, and sky. No life forms serve to soften the shapes and textures. Such will be the case on Mars - until such time as someone decides to terraform it.

For me, the lighting after 11:00 PM starts to get rather nice. The most beautiful lighting is to be found as the sun moves lower - but improbably - to the North. With the sun lower on the horizon, shadows are longer and much more detail is visible than when the sun is higher in the sky. The colors are also much richer making things look all that much more Martian (even if the sky is a stunning blue) - or, if not Martian, certainly alien.

One of the ad hoc musical themes of this place has been the end titles from the film "Apollo 13" by James Horner. As I pulled out my iPod MP3 player and keyed up the music, I found the perfect place to stop and scan the horizon. To the east you can see the Mars Society's Hab looking every bit like the spaceship it is intended to simulate. Moving north and then west you see Base Camp - its tents, antennas, ATVs and other gear in an orderly yet slightly scattered array.

At the northern periphery of "downtown" sits the greenhouse. With its Lexan acting like a refractor it bends the ambient light in such a way as to glow against the backdrop of Devon Island. When limnologist Darlene Lim stepped off the plane today she told me that the greenhouse really stands out and "sparkles" as one makes a final approach to the landing strip.

In coming days I would see the greenhouse temporarily adopt - and then discard - a hundred different hues. Sometimes they'd magnify ambient colors. Other times, the greenhouse would contrast it surroundings. Again, this was much more noticeable around midnight.

Scanning further towards the west was my destination: Tent City. I reached my tent and crawled in. I crawled in my sleeping bag and put on my eye mask to cut down on the bright orange glow that permeates my tent. As I lay there I began to notice small imperfections in the otherwise black mask. There is only one way to describe these points of light: stars. I suddenly realized that in my entire life I have almost certainly never gone this long without seeing the stars. How curious: for such a space-minded group of people we are all deprived of a view of the universe we are all working so hard to prepare to explore.

This is such a strange place. Earlier tonight I walked down into a small river that runs out into Von Braun Planitia - just below and directly north of Base Camp. With the exception of the trickle of water, the surface was a dead ringer for all of those Viking and Pathfinder photos of the surface of Mars. For that matter, this entire place can be described this way. All you need is some slight tinting in Photoshop and virtually any photo could pass for one of the surface of Mars.

This is also an odd place for humans. The sun does not set. I am a mammal that has spent its entire life in an environment wherein each day is punctuated - and separated from the next by night. The first day in Resolute was odd but was quickly remedied by ultra-dark window shades in my room.

Dave Herera (our first Camp Doctor) and I spent quite a lot of time on our first "night" in Resolute looking out the window after midnight. We both found it hard to shake the notion of what time it was and how bright it was outside. We also both thought it odd that people (women and their little kids) would be outside playing this late at night. From what I was later to learn, people relish nice sunny weather here and take advantage of it - whenever it occurs.

Here, you are at the mercy of constant sunlight. Within a day or so I had adapted: night blinds, earplugs, and 3 mg of melatonin and I slept a perfectly restful 8 hours. I am one of those people who can sleep absolutely anywhere - airplanes, subways - even once in a dentist's chair. Yet here on Devon Island, I had to time things to my watch. Unless I take a few steps to prepare for sleep the constant sunlight serves to lure me to stay awake - without fatigue.

Curiously even if one adopts an 8 hours of sleep/16 hours of wakefulness schedule, the constant sunlight allows you to experience additional moods over the course of a day. Imagine the longest day of the summer - when the days are so long you catch yourself looking at your watch and saying - "gee, look how late it is." You then sit back and relish the extra amount of daylight and the long shadows I casts. Imagine that feeling extended endlessly.

Odds are that the first human missions to Mars will land much closer to Mars' equator than we are to Earth's. As such, with virtually identical days, and thinner air, human crews are likely to note little disturbance in their day/night cycles.

However, there is some similarity between this place and what the crews will experience traveling to and from Mars. In Earth orbit, there is a day/night cycle of sorts - even if it cycles once every 90 minutes. At some point, astronauts need to block this out and sleep. Traveling to Mars, astronauts will experience the same constant lighting we experience - unless they take the same steps we do to block light (if need be) and live by the clock.